This invention relates to biopsy forceps for use in various medical applications, wherein a remotely operable pair of pivotally interconnected levers or tongs with cups or jaws at their outer ends are carried at the end of a thin, elongated sheath or tube. The cups or jaws are adapted to be inserted in a patient while in a closed position and moved to a predetermined internal location. While so positioned, they are manipulated by medical personnel using a control wire extending through the sheath, to capture a sample of tissue. More particularly, the invention provides a unique, simplified operating mechanism for the levers or tongs that minimizes the space required for manipulating the instrument and that renders the device practically disposable in order to reduce the risk of infection that could occur from reuse of the instrument.
Various types of biopsy forceps are currently in use in the medical field, such as in endoscopic procedures. These devices generally include gastroscopes, colonoscopes, sigmoidoscopes, and bronchoscopes, for example. They generally include a pair of levers or tongs that pivot relative to one another between open and closed positions to bring a pair of cup-shaped jaws together to capture a sample of tissue. The instrument also includes a long, resilient, flexible sheath that may be from 100 to 250 centimeters in length.
The head assembly that includes the jaws is carried at the end of the flexible sheath and is inserted in the patient at a desired position in accordance with the procedure to be performed. The jaws are closed during the insertion. When the head assembly is suitably positioned, the jaws are opened by the medical operator, using an elongated wire or cable that extends through the sheath. The operator then closes the jaws, using the control wire or cable to capture a sample of tissue between the jaws. In some cases, the instrument has a barbed needle extending forwardly of the open jaws and located between them to "spear" a sample of tissue and effectively "pull" it between the jaws as they close. The jaws are relatively sharp to enable the sample to be cut free from the surrounding tissue.
The biopsy forceps currently in use are generally of complicated design, with numerous components and, as a consequence, are quite expensive. More importantly, these instruments must be carefully sterilized after each use to enable the device to be used safely with another patient. The sterilizing procedures generally include immersing the contaminated biopsy forceps in chemical sterilizing solutions and/or placing the device in an autoclave. Unfortunately, these conventional sterilizing procedures have recently been found to be imperfect and, upon occasion, the instruments, when reused, have caused the transmission of serious, and even life-threatening, infections. Of particular concern is the risk of transmission of the AIDS virus (acquired immunity deficiency syndrome) or hepatitis B viruses. Also, in some instances, the extreme temperatures often present in an autoclave may cause damage and/or warping of the instrument in such a way as to prevent its proper operation.
As a result of the above considerations, it would appear desirable to have the biopsy forceps so designed and assembled as to make it practical to dispose of them after each use. This would be impractical unless the design of the forceps is sufficiently simplified that disposability becomes cost-effective.